Level set approach for the simulation of focused ion beam processing on the micro/nano scale

The level set method, introduced by Osher and Sethian (1988 J. Comput. Phys. 79 12-49), has recently become popular in the simulation of etching, deposition and photolithography processes in semiconductor manufacturing, as it is a highly robust and accurate computational technique for tracking moving interfaces. In this paper, the level set approach is applied to focused ion beam fabrication, allowing for the first time the simulation of targets with sub-regions that change their connectivity during processing. It is implemented in the code AMADEUS-level set (advanced modelling and design environment for sputter processes), which is capable of simulating surface topography changes in two dimensions taking re-deposition fluxes into account. We present two examples of comparisons between simulation and experiment that demonstrate the predictive capability of the code.